U.S. Pat. No. 3,445,257 to Hloch et al describes condensed aluminum phosphates used as hardeners for water glass cements. The condensed aluminum phosphates are prepared by subjecting aluminum orthophosphates to a stepwise thermal treatment. The cements are prepared from potash or soda water glasses by mixing 90 to 100 parts filler with 4 parts hardener, and then adding 25 to 30 parts of water glass. A typical cement has a pot life of 30 minutes and then cures within 24 hours to form a mass that is resistant to acids and water.
U.S. Pat. No. 3,930,876 to Nakajima et al discloses an improved silica-phosphate type inorganic coating composition comprising a water soluble silicate and an inorganic phosphate pretreated with such silicate. The pretreatment is accomplished by mixing the phosphate, in powder form, with an aqueous solution of the silicate in a mechanical mill. Filler and/or pigment in amounts of 60 percent by weight or less based on the weight of the pretreated phosphate may be added during or after the pretreatment of the phosphate. About 60 to 150 parts by weight of the pretreated phosphate and 100 parts by weight of silicate are then mixed together to form a uniform composition generally having a water content of 1/4 to 2 parts by weight water per part of total solids.
U.S. Pat. Nos. 3,869,198 and 3,951,525 to Ballentine relate to durable glass spandrels provided with transparent light and heat reflective coatings and substantially opaque ceramic enamel coatings to produce aesthetically matched vision and spandrel areas in curtainwall construction by utilizing a ceramic enamel coating which reflects light in the same spectral region as light transmitted by the transparent coating and glass in combination. Commercially available ceramic enamels are disclosed.